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Answer:
b = -10
<M = 90
<N = 50
<O = 40
Step-by-step explanation:
The sum of the angles of a triangle add to 180
<M + <N + <O = 180
90 + -3b+20 + -3b +10 = 180
Combine like terms
120 -6b = 180
Subtract 120 from each side
120-120 -6b = 180-120
-6b = 60
Divide by -6
-6b/-6 = 60/-6
b = -10
<M = 90
<N = -3b +20 = -3(-10) +20 = 30+20 = 50
<O = -3b +10 = -3(-10)+10 = 30+10 = 40
Step-by-step explanation:
[tex]90 + ( - 3b + 10) + ( - 3b + 20) = 180 \\ 90 - 3b + 10 - 3b + 20 = 180 \\ 90 + 10 + 20 - 3b - 3b = 180 \\ 120 - 6b = 180 \\ - 6b = 180 - 120 \\ - 6b = 60 \\ \frac{ - 6b}{ - 6} = \frac{60}{ - 6} \\ b = - 10[/tex]